Corrected entry: It is established at the start of the movie that the Klingon Bird of Prey is the same one that they flew to Vulcan in Star Trek III: Search for Spock. The bridge of the ship however is totally and utterly different to the one shown in the previous movie. There can be no claim to suggest they remodelled it in their time on Vulcan, because everyone still uses the controls with a degree of caution, which they wouldn't do if they modified it to suit their needs.
GalahadFairlight
27th May 2009
Correction: There most certainly can be made a claim that they remodeled it on Vulcan. What difference does it make if they, "use the controls with a great deal of caution?" People use brand new things and things they are already familiar with a great deal of caution. And this measurement is highly subjective at best. The crew is likely a bit apprehensive because the "guts" of the ship, for lack of a better term, are still Klingon. Scotty even speaks negatively of the dilithium crystals in the ship at point.